RollaCosta
Active member
What’s wrong with consulting the Rider’s Manual, pp.55-56?I am not familiar with 'ASC CAL'
What’s wrong with consulting the Rider’s Manual, pp.55-56?I am not familiar with 'ASC CAL'
The washers belong there in the rear casing.So today I put in the next size chain rail and put in fresh gear oil. The old oil was quite dark. I also put in a fresh axle seal. The odd thing was, there was one bolt missing from the final drive case cover, and two had a small washer where the other ones did not. As if someone had been in there before me. Even though I bought the bike with only 1,960 miles on the clock, two years old and I never took it for any maintenance to BMW, have done all myself. I've only had some warranty and recall work done by BMW. So ... I put in the new no. 2 rail, assuming that the rail that was in there was the no. 1. But after I got it all buttoned back up, and took another look at the rail I had just taken out, I discovered that that was a number 2 also! Not the original no. 1. So clearly someone had been in there before me, and my best guess now is that it was the first owner who took it to BMW with some sort of complaint, and they swapped in the no 2 rail. So, I opened it all back up, put in the no. 3 that I had also bought (I bought the whole set, nos. 1, 2, 3 and 4) and the second time took me only about 20 minutes.
I then tested to see if upping the chain rail had made any difference. I discovered that, when you rev the engine with the bike on the centerstand, you can actually simulate it going all the way to max speed - the speedo registers the hypothetical speed at the RPMs you rev it at. And, at around 90 MPH, the vibration starts and gets progressively worse until the bike starts to actually move on its center stand due to the vibrations, at 105 or so it's no fun anymore. So, the chain rail nor the new belt or rollers/sliders have made any difference. So, I think Rolla Costa is right, it must be something more fundamental in the engine: balance shaft, vibration damper, a not-exactly-straight shaft, worn bearing - something. But, since it is fine all the way up to around 85, I think I will leave it be for now, just monitor to see it doesn't get worse and I am also looking forward to riding the F800ST that has more power and a higher top-end, hopefully without vibrations! It's also possible, perhaps, that the rear wheel is slightly out of round, or the tire is not balanced properly - I can have those things checked out still.
Thank you for the info i will get the rear tire replaced probably in about 1 month orSo I think I am onto the cause: on the highway today I tested through to 100 mph and the vibration is definitely much less, although still present, but importantly it's now also clear that what is remaining is coming from the rear of the bike, not the middle (= engine) as I thought before. The reason it 'moved' was, I think, before I had the rear tire balanced, the vibration was so pronounced that the whole bike started to vibrate. Now that it's much less, only the rear is affected.
Which means two possible remaining causes IMO:
- the rear wheel bearings need replacing. There is indeed a tiny bit of play there in the wheel
- the actual tire itself has an irregular shape of sorts
- a combination of the two: as the tire is not perfect, any vibration is aggrevated by the small amount of play in the wheel bearings
All this makes sense to me, and also that it only starts at relatively high speeds, not at higher engine RPM.
For my next move, I will replace the wheel bearings and see what that does. If still not to my liking, I will get a new tire. The current one I only put on last year, but it's a Shinko el-cheapo, with which so far I have been satisfied (except that, in the wet, they slide quite easily) but if I need to put on a premium brand, I will happily do so if that eliminates the issue.
For now quite relieved that this is likely the cause, and not something deep within the engine block!
As it was time for a service, I changed the oil+filter, and also put in a new air filter (so, off came a lot of the tupperware on the right side. I had to remove the top side cover anyway to get at the OBD plug to reset the service warning with my Motoscan app). On my next longer run I will do the ASC recalibration.
There are only 2 washers if I remember and they go at the front end of the chain casing on the angled spaceThanks, well the washers were all missing except two random ones. No leaks though. I did replace the missing one in the center with a suitable bolt and there was thread for it in the casing.
Have you thought that you may have damaged the axel hamering it to break the inner race the hammering the inner race back on. It is fragile and thin walled.I had recently gone through all the same iterations as Ceesie76 is now. The 12-point socket is a 46mm to get the axle off. I used the old fashioned way of cutting an "X" on the inner race and break it with a chisel. Driving the inner race back on, I found a 1-1/2 inch pipe is perfect for seating the race and the outer sealed bearing. After all this, I had the tires rebalanced. When all is said and done, I still have some vibration, though diminished.
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